An oilfield sub (or “sub”) is a short joint of pipe (1′-10′) used to lengthen a pipe string, change from one size of pipe to another, reduce the ID of the pipe, or add a tool to the string. The terminal ends of each sub will have internal or external threads to allow for attaching the sub. Lifting a sub has previously been done by either wrapping a sling around the sub to lift it or by threading an eyelet plug or collar to one of the threaded ends of the sub and lifting the sub from the attached eyelet plug or collar. However, the threading on subs varies, and it can be difficult to identify a suitable lifting plug or collar for a particular sub. Consequently, an improper sized plug or collar could be used, creating the possibility of a sub slipping off the lifting plug or collar when lifted. Because the subs are heavy and awkward to move, both lifting methods present safety hazards.
Subs are usually placed in an “offshore basket” or junk basket for storage and shipping. The subs are stacked sidewise one on top of another. Removing subs from such a basket can result in injury due to the effort needed to retrieve a stored dub. One sub or many being may be placed on top of the needed sub, resulting in stored subs being rolled, picked up, or removed from the basket in order to get the desired sub. Hands and fingers can be injured in this process, and the sub's threading can be damaged by this type of handling.